The add-ons are created by third-party developers and allow users to do things like sign documents, create customized email templates or make name tags from within documents and spreadsheets.

With the EasyBib bibliography add-on, for example, users can create bibliographies by searching the web for sources, choosing a style and inserting a formatted bibliography without ever leaving the document.

Users need to select the new “Add-ons” tab from within a doc or spreadsheet, then hit “get add-ons.” From there, users can choose from the few dozen apps currently available in both app stores. Once an add-on is installed, it can be used from within any document in Google Drive.

The feature is currently in developer preview phase, which means though anyone can create an add-on, developers must be approved by Google in order to publish them to the marketplace. Once the preview phase is over, any developer will be able to publish an app to the add-on stores for Docs and Spreadsheets.